Dutasteride (marketed as AvodartÂ®, AvidartÂ®, AvolveÂ®, DuagenÂ®, DutasÂ®, DutagenÂ®, DuprostÂ®) is a 5-alpha-reductase inhibitor, a drug which inhibits the conversion of testosterone into dihydrotestosterone (DHT). It is used to treat conditions caused by DHT, such as benign prostatic hyperplasia.